1. Field of the Invention
This invention relates to the art of filtration wherein foreign matter is separated from a liquid flow.
2. Description of the Prior Art
Liquid filtration wherein foreign matter is separated from a liquid is well known. One widely used filter device includes a tank having a pervious bottom which connects with an inclined ramp end wall.
Liquid containing foreign matter is pumped into the tank. As the liquid flows through the bottom, the foreign matter is retained. The tank typically includes a conveyor which comprises a series of transversely positioned flights. Periodically the conveyor is energized so that the flights move across the pervious bottom to remove the foreign material collected thereon. The removed foreign matter is then transported up the ramp by the flights for external disposition.
Where the foreign matter includes particulate having a small particle size or tramp oils, it is common to use a filter media sheet to effect foreign matter retention. The media sheet may be either of a permanent or disposable type and interfaces between the conveyor flights and the pervious bottom and inclined ramp.
Such a liquid filtration device is presently marketed by the assignee herein under the trademark HYDRO-VAC. Early examples of this filter type are set forth in U.S. Pat. Nos. 3,087,620, 3,091,336 and 3,332,556. Also see U.S. Pat. No. 4,250,036 which describes an improved conveyor for use with this type of filter device.